PJ forum are 64x64 max but can be smaller, so don't sweat that. I actually think you are kinda ok with these colors. If anything one extra grey or dull blue grey to blend the darker green to the blue might be fine. Or change that darker green with a desaturated color. You just gotta play with that shade till your eye say yes.

Ahhh sorry should have explained the cropping, I made it so it would fit another forum as well which only has an avatar size of 50x50.

I wanted to saturate it more but I wanted it to also wor as an AA colour on the outside. I did this beause this is also my first real attempt at AA apart from one other piece. Any sugestions on the colour?

I'm still pretty novice as a pixelartist. I suppose I could make the tiny pic which I think is used as avatars here bigger to suit this forum and leave the detailed file small but that would seem odd? No?

I might fiddle with the hues a bit more.

I think your problem is THAT green and THAT red. Using neutrals can easily make green + red flow, its been done.

Why you didn't make the whole moon and instead cropped it, is more of a problem for me than the colors on this piece.